1. Field of the Invention
The present invention relates to an optical component fixing method and an optical component support for use in an optical apparatus equipped with at least one optical component and optical component support, particularly to a fixing method used when an optical component is fixed to a support by an adhesive and the support to which the optical component is fixed.
2. Description of the Related Art
In order to ensure stable laser emission, the length of the laser resonator must be kept from varying greatly with change in ambient temperature. This is achieved, for example, by temperature-controlling the resonator section. When the layer of adhesive between a resonator mirror and the retaining member is thick, however, thermal stress is produced by the difference in thermal expansion coefficient between the retaining member and the mirror. Since this increases the adhesive contraction during hardening, the resonator length cannot be kept constant. Change in the resonator length causes fluctuation in the laser output and the longitudinal mode and/or induces noise. Stable lasing cannot be maintained under these conditions change in resonator length therefore must be held to within ¼ of the wavelength of the laser light. Considering the fact that many semiconductor-laser-pumped solid state lasers emit light of a wavelength around 1 μm, change in resonator length should ideally be kept under around 0.25 μm.
Applicant's Japanese Unexamined Patent Publication No. 8(1996)-186308 teaches a Fabry-Perot resonator that has its resonator mirrors adhered to opposite ends of the resonator retaining member and that is enabled to maintain a constant resonator length by keeping the thickness of the adhesive layers at not greater than 5 μm and the roughness of the machined surface of the retaining member at not greater than the wavelength of the laser light. In an optical apparatus that, like this semiconductor-laser-pumped solid state laser, requires precise positional adjustment and fixing of an optical component, the fixing of the optical component by use of a fluid adhesive must be carried out by uniformly flowing the adhesive between the optical component and its support. To ensure formation of a uniform adhesive layer, therefore, the practice is to facilitate the flow of the adhesive by finely polishing the attachment surfaces of the optical component and the support.
However, the fine polishing of the attachment surfaces of the optical component and support involves considerable cost and is therefore economically disadvantageous.